


Want You Need You

by Joths_Dump



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alpha/Beta/Omega Dynamics, Anal Sex, Beta Dedue, Beta/Omega, Biting, Bottom Sylvain, Friends With Benefits, M/M, Mating Cycles/In Heat, Omega Sylvain, Post-Timeskip | War Phase (Fire Emblem: Three Houses), Rimming, Self-Lubrication, but it gets kind of affectionate, minimal lubrication
Language: English
Status: Completed
Published: 2020-05-07
Updated: 2020-05-07
Packaged: 2021-03-02 21:41:47
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,128
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24053824
Author URL: https://archiveofourown.org/users/Joths_Dump/pseuds/Joths_Dump
Summary: Poor Sylvain, he's been hit with a sudden and nasty heat. Luckily for him there is a big strong knight who is more than willing to fuck some sense into him.Yeah you heard me, Omegaverse Syldue baby!A one-off Inspired by the omegasylvainweek.
Relationships: Sylvain Jose Gautier/Dedue Molinaro
Comments: 4
Kudos: 44





	Want You Need You

Sylvain sat comfortably on the mattress. He already stripped himself of every piece of cloth and leather on his body. He glistened with set and was cherry red with warmth. His nipples were perky and almost looked swollen. His long-toned legs were spread wide showing off his fully erect cock. He eased back to get a good look at his partner for the evening. 

Dedue’s body was that of a bronzed god. Massive and hardened with battle. Dusted with silver hairs and silver scars. He was fumbling with his trousers, fighting through the anticipation and anxiety. When he finally pulled them down with his smallclothes following close behind, Sylvain couldn’t help but belt out a long-drawn whistle. Even at half chub Dedue’s cock was huge.

Sylvain couldn’t help but tease, “You sure you aren’t an Alpha?” 

“I am certainly not.” Dedue huffed. “But I will help fill you up all the same.”  
-  
When Sylvain woke up that morning, he knew he had it bad. Having a vivid dream about being pinned down and humped like a beast only to violently wake up covered in sweat and an intense fire in his loins usually indicated a fierce heat. There was no way he could go the whole day with out someone to bang it out of him. He got out of bed ignoring how the sheets and pillows were in disarray, and put on loose-fitting clothes and some slippers. He immediately charged out the door only to be hit by a harsh realization. The Professor…err, the Acting Archbishop and Resistance General said they were taking a squad of former students to take care of bandits and imperial stragglers in the newly reacquired Blaiddyd territory. This meant his go to partners for days like this wouldn’t be available. Sylvain planted his face on the doorframe and groaned in both kinds of frustration. What The FUCK was he going to do now? He tried to remember who was going with Byleth, and by process of elimination find out who would still be here at the monastery. It was then he realized he had the perfect partner, Dedue.

He lifted his head up and sprinted to the stairs and then stampeded down them. When he reached the bottom, he saw Bernadetta, who was walking back to her dorm with her sketchbook in hand when she stopped in shock upon Sylvain’s dynamic arrival.

“Sy-Sylvain! Don’t scare me like that! Are you trying to hurt yourself!”

“Bernadetta that doesn’t matter right now.” He was too worried by his approaching heat to care about such “trivial” matters.

“Hmph!” she hmphed. “Where were you this morning? You missed breakfast and weren’t there to see off the Professor and their troop. That’s so unlike you…” she mumbled the last bit. It’s true, whenever he wasn’t on the field team for a mission, he always made sure to see off his friends that were. “His Highness, Felix, and Ingrid were worried about you.”

Sylvain sighed, “I… I had a rough night.” Hearing that he upset his friends like that didn’t exactly make him feel any better. But there were more pressing matters to attend to. “I need to find Dedue, have you seen him?” 

“Huh? Oh… yeah. Right before I left the greenhouse he was coming in for the-“

“THANKS! SEE YOU LATER!” Sylvain shouted as he ran as fast as a horse to the greenhouse. Leaving poor Bernie dumbfounded.  
-

When he reached the doors of the greenhouse, he slammed them open. Naturally, Dedue was shocked. Without missing a beat, he dropped his tools and turned towards the door with his fists curled and ready to pummel the “intruder.” Once he realized it was just Sylvain, he wrinkled his brow in frustration. “Sylvain, could you please be more careful? You could have broken the doors. What is the matter?”

Fortunately, they were the only two people there at the moment. Sylvain sauntered to Dedue’s position and got surprisingly close. “I need your help.”

Dedue just raised his eyebrow until he got a better look at Sylvain. He could see how red and sweaty Sylvain was. “Are you ill? Manuela stayed behind at the clinic so you should…”

“No. Only you can help me right now.” This made Dedue only more confused, so Sylvain closed the distance even further, to the point that he was almost in direct contact with Dedue. He pulled the collar of his shirt to the left, exposing the furiously-swollen red gland and freeing his scent enough to compete with the herbs and flowers. Dedue unthinkingly to a deep inhale of his scent. He smelled of cinnamon and an open flame. Unconsciously Dedue sighed in delight at the heady and enticing aroma. Sylvain’s face had a devilish grin plastered on it. 

“Do you…” Dedue stuttered, “Do you want to use me?” 

Sylvain winced when he said it. “N-no I don’t mean…” he sighed painfully, “Where friends right?” They may have not done much together in the past without the rest of their shared friends. In the years spent without any interaction didn’t help much. But Sylvain still brought Dedue into a big warm welcome back hug as soon as he got the chance. They continued to trust each other on the battlefield. Vent when they had a hard day. Joke with one another. Share their hopes for the future together. “I… this is really really bad. Right now, you’re the only person I trust to help me through this.” There wasn’t a trace of insincerity in his words and tone.

Dedue was blushing. Hard. “I see… but you must understand that I am still a Beta and may be ill suited to… treat you, during your rut.”

It was then that the light flickered on in Sylvain’s head. “Oh! You think…” Sylvain’s face began to redden further, but this time from embarrassment and not his heat. He spoke in a whisper “I’m an Omega.”

Dedue’s eyes blew wide open and his jaw dropped open. “But you…”

“Yeah…”

“And you…”

“Yep.” Sylvain groaned in embarrassment. “I know the whole shtick; there’s no way an indiscriminate philanderer like me is an Omega.” Sylvain looked down with a horridly dour expression, “I know I’m a dirty hypocrite.”

Dedue’s face weighed heavy with sorrow. “Sylvain I did not mean to…” as he spoke he placed his left hand over Sylvain’s right shoulder. He was terrifyingly warm and even leaned into the larger man’s delicate touch and moaned.

“Mmmmm.”

“Oh. Sylvain, you poor… I can, no I will, help you through this.” Dedue spoke with the same unwavering confidence he used when he spoke of his duty to his Highness or Duscur. Sylvain couldn’t help but gaze at him longingly. And dopily. He knew he could rely on his big, strong, unshakeable, masculine, domestic, warm, and dignified companion. “Come now, let’s get you back to your room.”

“Umm… I didn’t eat anything this morning. And I think I’m running out of time before it really begins.” Sylvain sheepishly admitted. 

“I see… Well that won’t be a problem. Come with me.” Dedue took Sylvain’s hand in his own and walked him out the greenhouse. As they walked across the grounds, they made sure to remain discreet and not alert anyone. After a good long walk, they stopped in front of Dedue’s dorm room. Sylvain had bent all the way over with exhaustion, all the while panting like a dog. He already exerted himself far too much and his heat was only getting worse. Dedue didn’t want to push Sylvain so hard. He looked around to make sure the coast was clear. When he was certain they were fine, he lifted Sylvain like a bride. Sylvain just looked up into Dedue’s warm gaze, he was hopelessly enamored. Dedue carefully carried him inside. He walked over to the bed and gently laid down Sylvain. He walked over to his desk and pulled out a square tin. He dragged his chair behind him and sat down by Sylvain.

“Here, these should tide you over for now.” He opened the tin, presenting a medley of dried fruits, jerky, and tea biscuits.

“Thank you so much.” Sylvain reached out his hand but then paused. “Why do you have these?”

“Ah well. For someone of my size, I need to eat quite a bit.” Dedue then averted eye contact, “and I didn’t want to look improper…” Sylvain’s eyes began to tear up. “No, it’s fine.” Dedue hoped to assuage his worries. “That is no longer a problem. It has just become a habit. Plus, the Professor sometimes likes to come in for tea.”

Sylvain sniffled. That did help him feel a bit better, but he still couldn’t help but feel awful that he didn’t understand how much he failed to recognize his friend’s misfortune.

Dedue picked out a slice of peach and held it out in front of Sylvain. “Here.” His smile was broad and comforting. Much to his surprise, Sylvain did more than just grab the slice. He grabbed Dedue’s hand and brought it to his lips. Dedue got the message, Sylvain opened his mouth and Dedue eased it in between his lips. Sylvain gently bit into the fruit and chewed. 

They continued like this for a few more pieces of food never breaking contact. Until Sylvain held his hand up and blocked anymore food. “Enough. Thirsty.” Dedue nodded for confirmation and walked back to his desk. He picked up the water flask off of it.

“Shit.” It was empty. “I’m sorry, will you be fine if I go out to get you some more water?”

“Ye-yeah. If anything happens, I can at least use some magic.” Sylvain assured him.

Dedue nodded and slipped out the door.

-

He was only gone for a few minutes before he returned. He carefully knocked on the door and announced himself, “I have returned. I’ve brought two full flasks.”

“Come in~” Sylvain answered in a sing song voice. When Dedue opened the door and saw inside he gasped. He squeezed through the door and locked it behind himself. He turned back towards Sylvain, who was still laying on the bed but now completely naked. Dedue didn’t even mind the clothes messily tossed around the room. Sylvain’s scent had already begun to spread throughout the room. Dedue knew that if he had an Alpha, or even an Omega’s sense of smell, it would have been so intense that it would drive him into a frenzy. Dedue quickly walked over and handed Sylvain one of the flasks. “Thank you.”

“Buh…” Dedue fumbled his words. He just gave a thumb up and took the tin of food, the chair, and the extra flask back to the desk. He turned back around to face Sylvain and take him all in. 

Dedue decided to start from Sylvain’s head and slowly bring his attention further down. He got a better look at Syl’s wide shoulders and broad chest. Little red hairs dotted the surface of his chest. Sylvain’s nipples were hard and begging to be bitten. Sylvain noticed where Dedue was looking and circled his fingers around his nipples. Dedue gulped and continued take in his “meal.” He admired Syl’s washboard abs with more of the deep red hair in a generous trail from his navel down to his… Dedue skipped back down to Syl’s calves. Earning a pout. He slowly worked his eyes back up towards those not-very wide but nonetheless incredible dense with muscle thighs, that he would love to sink his teeth in. Finally, he couldn’t ignore Sylvain’s dick. Though he was an Omega, he still had a fine dick (granted size differences between the secondary genders were largely exaggerated.) It stood up proudly in the air, long and of healthy girth. His balls were loose and sagging to relieve heat. Sylvain put on a show by slowly stroking his length. “Come on big guy~” he smiled like a wicked devil, “don’t keep me waiting.”

Dedue grabbed at the buttons of his shirt and with great agility and deftness opened each one and took off his shirt. Sylvain sat up and hung his legs over the bed, to get a better view. He made sure to spread his legs apart as far as possible to make sure Dedue didn’t lose sight of his goal. He eased back and gazed at Dedue’s form. He was one hell of a looker to. He was taller, broader, and beefier than Sylvain. Deep sunkissed skin, that was decorated with fierce battle scars and a generous fuzz of silver on his enormous pecs and between his navel and groin. Dedue fumbled with his trousers, but pulled them and his undergarments down. He may have somehow managed to resist becoming fully erect, but that didn’t make him any less impressive. He was certainly proportional.

“Phwee- phweeewww.” Sylvain whistled. “You sure you aren’t an Alpha?”

“I am certainly not. But I will help fill you up all the same.”

Damn he had quite the way with words. “Well then.” Sylvain laid all the way back down showing off his already loosening and moist hole. “Come and get some.”   
Dedue closed the distance between them in an instant. He got down on his knees, he was (sort of) eye level with Sylvain’s hole. He firmly grasped the interior of Sylvain’s thighs to hold him open and kissed his hole.

“Ohhhhh~” Sylvain moaned and shivered. Dedue continued by pressing the pad of his thumb against the rim of his hole. He gently massaged it, spreading his slick around. Just when Sylvain thought he was done, Dedue stuck his tongue in. “Mmmm.”

The taste was… not exactly pleasant. Dedue already figured that the natural lubricant of an Omega male, was cloyingly bitter. But he would be lying if he said he didn’t hope Sylvain’s wouldn’t be as bad.

But that wasn’t going to deter him. Dedue continued to rim Sylvain’s hole, and Syl was absolutely loving the warm and wet muscle lovingly caressing his inner being. He wasn’t used to receiving such kindness and gentleness when he bottoms. He felt that this alone could make him cum. But he bit down on his right fist and gathered all the will power he could muster. “That’s enough!” he choked out. 

Dedue complied, he drew his head back and stared directly into Syl’s eyes. He had a proud grin as he awaited his next request. Sylvain panted slowly and heavily before continuing, “I need you inside me. NOW!” How petulant. Nonetheless, Dedue was eager to please. He stood back up on his feet. He was now at full mast. Hell, it looked big enough to work as a mast. Sylvain shuddered in anticipation. He turned on his belly and crawled up the bed. As tempting as it was to get his ass blasted while it hanged over the edge, he really wanted to be smothered under Dedue’s full mass. As drew close to the pillows he felt the bed shift under Dedue’s added weight and before he could even realize what was happening, he felt Dedue’s large hands smack down on his ass cheeks. “OH!”

Dedue began to pull their bodies closer together, but Syl slowed him down. “Hold on! Hold on!” He grabbed a pillow and stuffed it under himself. It slid against his dick, causing him to flinch at little. He buried his head into the mattress, held the pillow up tight against his abdomen and cock, and heaved his ass into the air. “Now… go crazy!”

Dedue clawed into Syl’s cheeks again, and aligned himself. With one swift motion he buried his massive cock into Syl’s rosy hole. Dedue moaned and Sylvain cried out in sharp ecstasy. 

“You alright?” Dedue inquired.

“I am more than alright~” Sylvain hummed.

“Good.” Dedue thrusted in deeper all, the way to the base of his cock.

“Ahhh!” Sylvain cried once more. Dedue’s cock was almost too much to handle, it seemed to allow no space for air between it and the walls of Sylvain’s ass. Dedue recognized that Sylvain was enjoying his girth, and continued to pound deep in to him. Slowly as he continued to thrust into him. Dedue dragged his hands from Sylvain’s perky ass, up his spine, and around his waist. He wrapped his left arm around Syl’s abdomen. And dug his right hand between the pillow to grasp at the already raw and aching cock. Dedue enjoyed the full body shiver radiate from within Sylvain and into his own body. He now had full control over Sylvain; as he slammed into his ass he also fiercely stroked at his cock. He leaned his head into Syl’s right here and whispered in his low and rumbling voice, “You’re so good for me.”

All Sylvain could do was moan and immerse himself in the loud smacking of flesh against flesh. His eyes were beginning to weep with joy and immeasurable pleasure; so was his cock. “Dedue please…” he begged. “PLEASE!” 

“As you wish my dear,” he slipped out his dick to the tip. And in unison he bit into the junction of Sylvain’s neck and right shoulder and sunk his balls deep into him.

“AAAHHHHHHNNNNNN” Sylvain shouted like a banshee as he shot cum onto the sheets bellow. He felt like a bomb went off in his body as it seemed every nerve lit on fire.

Dedue gave a few more sharp overstimulating thrusts before it was his turn. “SYLVAIN!” he bellowed, as he released loads and loads of white hot cum inside. Filling him up to the brim and miraculously oozing between their flesh and out Syl’s hole.

They stayed there for a moment, panting. Soon Dedue slid all the way out and sat up on his knees. Sylvain yanked the pillow out from under him; his arms had started to numb making it a bit difficult. He turned over on his back. Dedue helped by lifting his upper body onto the cleaner pillows (not that Sylvain would have minded the soiled one.) Sylvain looked up lovingly at his giant companion. His face was red with heat, exhaustion, and achey tear ducts. Dedue leaned closer to Syl’s face, and stroked it with his hand.

“You know… it will be only be a couple minutes before I’ll need you again…” Sylvain admitted in embarrassment.

Dedue just chuckled. He moved his thumb to Sylvain’s lower lip to ease his mouth open. When Sylvain responded Dedue dove in with his lips and tongue. He passionately kissed and tongued Sylvain; when all Sylvain could do was remain passively dumfounded and moan.

Seconds felt like minutes, and eventually Dedue had to come back for air. “Would you still have me?” he questioned with a wide grin and bright blush.

“Gladly.” Sylvain chuckled. Dedue dove right back in.

**Author's Note:**

> God I have too much to say about this fic.
> 
> 1- I'm still working on Wyrm's Kiss.  
> 2- Dimitri is also an Omega and Felix is an Alpha. Dedue and Sylvain have already cut their teeth on those two respectively.   
> 3- While I said Sylvain is only use to meaner tops, Felix hasn't been mean deliberately. He lacks experience or knowledge and Sylvain's own hang-ups haven't helped that out at all.   
> 4- No lube except Omega slick. Not the best idea. These two will be applying tons of salve in the morning. Next time they'll think ahead.  
> 5- Sylvain takes contraceptives all the time. So he'll probably be fine on that front.


End file.
